Apparently one girl didn't make a cut to NewJeans, and if Ruka is the Haruka from Le Sserafim docu then yeah one which didn't make a cut.
I don't think all those girls are/were under HYBE labels before tho. Time flies fast in KPOP some are probably from auditions, some are scouted from free market, some taken from smaller labels or dance academies.
Ruka is Haruka from Le sserafim docu-series they even mentioned that she didn't make the cut in le sserafim in her introduction video